EP0880107A2 - Chip module for chipcard - Google Patents

Abstract

the chip module has a carrier substrate (2), at least one IC (4) on the carrier substrate and a cover (50 pref. pressed onto the substrate. The substrate has at least one opening (12) whose edge region (14) is shaped at least in sections to form at least one reverse cut (11. The covering material flows into the opening and reverse cut. The reverse cut is formed by making depressions in the rear (6) of the carrier film and corresp. raised parts (10) on the front side so that the deformed edge region protrudes over the plane spanned by the carrier substrate. At least part of the upward protruding edge region (14) is at an angle less than 90 degrees to the bounding flat edge region (13).

Description

The present invention relates to a chip module for a chip card according to the The preamble of claim 1. Furthermore, the invention relates to one of these Chip card comprising chip module according to claim 16.

Of the different ways to build chip modules have particularly enforced the procedures where the IC is based on a flexible film is mounted, which has the desired contact cables. When attaching the IC TAB technology (tape automated bonding) as well as wire bonding technology. However, this procedure is common that the IC must be sealed by a cover (capping). The cover is e.g. by plastic molding or other techniques upset. For example, moldable epoxy molding compounds. Examples for generic chip modules are known from DE-OS 30 29 667.

These chip modules are used in chip cards and are subject to loads there, which is also a major requirement for connecting the cover to the Place the carrier substrate. Especially when attaching the cover on one side The carrier substrate has to overcome some problems in this regard. E.g. has been suggested using an additional epoxy tape to bind to improve. However, such a proposal is for use in the Mass production too expensive.

A generic chip module is known from DE 690 13 220 T2. At a Embodiment are arranged in a metal band openings that the rear have undercuts assigned to the metal strip. In the Undercuts penetrate the plastic mass covering the chip to create a To anchor the plastic cover to the metal band. Another Embodiment shows a thin metal band with local depressions associated openings includes also for anchoring the plastic to serve.

From the German utility model 79 31 219 is a semiconductor device known, which has a metallic plate and a body made of plastic. Of the Plastic body closes at least one wafer made of semiconductor material and desired electrical connections. To ensure a good connection of the body Reaching plastic on the metal plate is essentially in the metal plate mushroom-shaped protrusions, on which the plastic body is anchored. This method already offers a reasonably good connection. However, must Considerable reshaping is carried out to design the projections, which, in order to prevent warping of the metal plate, places high demands on the Manufacturing technology.

In addition, chip modules of a chip card must have relatively high bending loads can endure. The known anchoring is disadvantageous with a relatively large Distance to the bending line of the metal plate, which is why relatively large forces on the Attachment point act and there is an early failure of the connection could come.

It is therefore the object of the present invention, one for mass production to provide a suitable chip module in which an improved connection of the Cover is carried out on the carrier substrate.

This object is achieved by a chip module according to the features of the Claim 1 solved.

If at least some of the upstanding edge areas are at an angle of have less than 90 ° to an adjacent flat edge region, then are undercuts are also formed by the course of the edge areas. This Edge areas are then similar to barbs from the covering material encapsulated and improve the anchorage again.

So that the flow of the covering material is simplified and the anchoring is further improved, the at least one undercut by embossing Indentations in the carrier film are shaped such that corresponding on the front Elevations are formed so that the deformed edge areas over that of protrude the plane spanned the carrier substrate. If the channels accordingly are deeply molded, the lateral opening areas of the channels are above the Level of the base film, so that the openings of a three-dimensional itself extending edge are bounded, which is completely in sections from Covering material is included.

Anchoring is also achieved, which is in the plane of the carrier substrate extends and therefore essentially no distance from the bending line of the Has carrier substrates. This causes only minor loads. The Cover material flows through the openings into the undercuts, causing the carrier substrate remains flat on the side of the undercuts can without requiring additional space. Such an arrangement is suitable in particular for the one-sided attachment of a cover to a carrier substrate.

According to one embodiment, the carrier substrate can be a carrier film. This Design is used in most applications and is one of them Technology widely used and well-proven form of application. By the relative Little deformation at the edge region of the openings is the present invention Technically favorable for relatively thin carrier films.

A particular advantage is given by a variant in which the carrier film is a Is leadframe. The leadframe can be used very well for shaping the openings and Use undercuts. Furthermore, a leadframe is cheap Process conditions ready because the chip modules in the individual Manufacturing steps remain lined up until the final separation.

A particularly favorable embodiment provides that the IC on an upper side of the Carrier film and the at least one undercut on a back of the Carrier film are arranged because in this construction, a one-sided cover is completely sufficient.

So that the back of the carrier film is flat and thus that Simplified insertion into the chip card, the cover material in the Undercuts and the openings essentially flat in the back of the Skip carrier film. This also has the advantage that the back of the carrier film only has to be pressed against a flat surface when forming the cover, to close the undercut in this direction and a leakage of the To prevent masking material.

The anchorage to the carrier film can be improved in that the Undercuts as a channel or arranged on the back of the carrier film arranged channels are formed. The channels can be completely covered Fill the masking material, creating an anchor on the back of the backing film takes place over a relatively large area and sections of the carrier film completely are cast into the cover.

The channels can be created by embossing recesses on the back of the Carrier film can be shaped. This procedure is easier and less expensive than molding the channels in another way, e.g. by Milling.

An embodiment has also proven to be favorable in terms of production technology, in which a channel extends from one opening to the next opening. The Covering material can then be uniform on the back of the carrier substrate Form anchoring element.

A particularly favorable embodiment provides that the openings on a Circular arc line are arranged and an essentially triangular or trapezoidal channel with the circular arc line as the center line in the carrier substrate is embossed. Such a symmetrical design allows placement of the IC right in the middle. In addition, there is a symmetrical embossing load, which prevents warping of the carrier substrate becomes. With such a configuration, e.g. one at the back in the channels arranged circular ring of covering material above itself through the openings extending webs connected to the cover on the top of the carrier film. The load requirements placed on such a chip module are straightforward achievable with this arrangement.

As already mentioned, the openings and the channels can be a receiving area limit on which the at least one IC is applied. The boundary can be in any suitable geometric shape, e.g. rectangular, circular or triangular respectively.

The openings can also be substantially in the form of an n-corner around the Recording area grouped around. It is important here that an even Connection of the carrier substrate with the cover is made by the openings are grouped accordingly around the IC.

The openings can have an n-shaped and / or circular cross section have what ultimately of the shape of the undercut to be trained depends.

So that the carrier film can be centered sufficiently during the manufacturing process, can create at least two openings with each other through a breakthrough be connected that the located between the at least two openings of the breakthrough material area of the carrier film as Hold-down tongue protrudes laterally over the cover. The possibility of Hold down immediately adjacent to the cover is particularly in the case of Manufacture of the cover applied pressures. By molding the Openings, the carrier film is somewhat weakened in this area, which means that Holding down and fixing the carrier film ensures the desired dimensional accuracy.

Holding down is particularly important if at least one Potential isolation channel is provided which at least in the area of the carrier film Coverage divided into separate areas, with at least one breakthrough Is part of the potential isolation channel. The different contact areas on the Carrier film must have sufficient potential separation, which is indicated by a Isolation channel takes place. This isolating channel can, however, depending on its Location, the recording area of the carrier film (or the corresponding contact trains), which is below the cover, cut into several parts. So yourself Do not discard these sections when forming the cover Isolation channel laid so that it makes a detour via at least one breakthrough makes so that at least the largest separated part of the recording area each has at least one corresponding hold-down tongue by means of which it is fixed can. The cover material also fills the isolation channel to improve the Isolation from. However, since this usually does not have any undercuts it does not serve to anchor the cover to the carrier film.

So that no cover material by the cover during the manufacturing process Potential separation channel can escape, this near the edge of the Cover have a removable web that the contact areas connects with each other. This web is then after the cover has hardened punched out again so that the potential isolation channel has its desired effect can unfold.

To better bend stresses from the IC and the anchorage of the cover To be able to keep away are in a further embodiment outside the Cover and around this spaced relief slots intended. In this way, forces introduced at the edge area of the chip module or transmit moments far less effectively to the recording area.

Furthermore, the invention relates to a chip card with a chip module one of claims 1 to 15. It should be noted that the invention applies to both Chip cards with contact areas as well as on contactless cards or hybrid cards is applicable. The chip modules are preferably placed in milled pockets Smart cards introduced.

But there is also the possibility of using the cover immediately as a chip card to train, of course receiving the anchorage according to the invention remains. Such a configuration would be particularly suitable for a mini chip card ID-000 format. However, the manufacture of others is more common Chip card formats conceivable. At least the basic body of the chip card can be such be produced and provided with appropriate surface layers.

The chip module can be produced by a method in which at least one IC attached to a carrier substrate and one with the carrier substrate connected, preferably manufactured by means of compression molding, covered becomes. The method is characterized in that openings in the carrier substrate are introduced, the edge regions of which at least in sections to form Undercuts are formed into when making the cover covering material flowing through the openings flows into it.

This procedure makes it possible to attach the cover to one side Attach carrier substrate and still anchor to the back. The The method is ideal for the mass production of chip modules for a chip card, since it is a simple procedure.

The undercuts can advantageously be produced by a stamping / embossing process getting produced. It is characteristic of the method in particular that of the Geometry ago only relatively simple punchings and impressions made must be in order to achieve the corresponding effect.

Another preferred method step is that the undercuts are generated by impressing channels that have corresponding elevations on the Throw up opposite side of the carrier substrate. These increases will be then essentially completely of the covering material, that is also of the Channel side ago, included. As a result, areas of the carrier substrate integrated within the cover and ensure the desired connection.

A further method step has proven to be advantageous in which the channels be completely filled with masking material, with the mold cavity to be filled Channels by pressing the carrier substrate onto a substantially flat Form pad is closed on one side. From the back of the carrier substrate So there are no special formal requirements to be met. Rather, one is enough level mold plate completely to achieve the desired molding pressure. The Channels themselves form the mold cavities that are filled with cover material.

Fig. 1

ein erfindungsgemäßes Chipmodul in Draht-Bond-Technik in einer Querschnittsansicht,

Fig. 2

eine Querschnittsansicht durch ein Trägersubstrat mit angebrachter Abdeckung, außerhalb des IC-Bereiches geschnitten,

Fig. 3

eine Stanzmaske des Trägersubstrats gemäß Figur 2 in einer Draufsicht,

Fig. 4

eine Ausführungsform der Öffnungen in dem Trägersubstrat vor dem Prägevorgang,

Fig. 5

die Ausführungsform aus Figur 4 nach dem Prägevorgang,

Fig. 6

eine Querschnittsansicht entlang der Linie VI-VI der Figur 5 geschnitten,

Fig. 7

eine weitere Ausführungsform des Trägersubstrates in einer perspektivischen Draufsicht,

Fig. 8

die Ausführungsform aus Figur 7 in einer perspektivischen Unteransicht,

Fig. 9

das Trägersubstrat aus Figur 8 mit angespritzter Abdeckung,

Fig. 10

ein Chipkartengrundkörper vor dem Einsetzen des Chipmoduls und

Fig. 11

eine vergrößerte Querschnittsansicht der Aufnahmevertiefung am Chipkartengrundkörper vor dem Einsetzen des Chipmoduls.

Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. Show it:

Fig. 1

an inventive chip module in wire bond technology in a cross-sectional view,

Fig. 2

3 shows a cross-sectional view through a carrier substrate with the cover attached, cut outside the IC region,

Fig. 3

2 shows a stamping mask of the carrier substrate according to FIG. 2 in a top view,

Fig. 4

one embodiment of the openings in the carrier substrate before the embossing process,

Fig. 5

the embodiment of Figure 4 after the embossing process,

Fig. 6

5 shows a cross-sectional view along the line VI-VI of FIG. 5,

Fig. 7

another embodiment of the carrier substrate in a perspective top view,

Fig. 8

the embodiment of Figure 7 in a perspective bottom view,

Fig. 9

8 the carrier substrate from FIG. 8 with a molded-on cover,

Fig. 10

a chip card body before inserting the chip module and

Fig. 11

an enlarged cross-sectional view of the receiving recess on the chip card body before inserting the chip module.

FIG. 1 shows a chip module 1 which essentially consists of a carrier film 2, an IC 4 arranged on the top 3 of the carrier film and an IC 4 surrounding cover 5 consists of a plastic material. On the bottom 6 of the carrier film 2 are the contact points 7 in this exemplary embodiment upset. The carrier film 2 extends next to the IC 4 Through openings 8, through which bond wires 9 contacted with IC 4 passed through and connected to the contact points 7. The cover 5 surrounds likewise the bond wires 9 and their connection points.

In the carrier film 2 raised locking areas 10 are embossed, which are still in following described in more detail also from the covering material of the Cover 5 are surrounded. For this purpose, form on the underside 6 of the carrier film 2 through the embossing channels 11, which are filled accordingly with covering material are.

The functioning of the locking areas 10 will now be explained in more detail with reference to FIGS. 4 to 6 explained. In these figures, only the carrier film 2 is for the better Illustrated. In these locking openings 12 are punched, the two parallel sides 13 and four each at an acute angle α to the sides 13 have arranged transverse sides 14. The locking holes can be seen in the top view 12 like a double dovetail, with the short straight sides of the Dovetails are identical and sides 13 are the spaced, long ones Form sides of the dovetails. The transverse pages 14 that belong together form a corner 15 such that the two corners 15 face each other and one Form the edge component of the locking opening 12.

In FIG. 4, the locking openings 12 are before a subsequent stamping step shown.

The embossing is carried out by means of a stamp which is triangular or trapezoidal in cross section essentially symmetrical to the center line M from the underside 6 of the carrier film 2 forth. As a result, the webs remaining between the locking openings 12 are aligned to the locking areas 10 mentioned. The locking areas 10 then have approximately the shape of a tent, with the edge areas considered in the side view 13, 14 of the locking openings 12 each have a dovetail shape have corresponding undercuts 16. The corners 15 have one less distance than the undercuts 16, so that they on locking hooks form the top 3 of the carrier film 2. On the bottom or back 6 include the Locking areas 10 also undercuts in the form of the channels mentioned 11.

As can be seen from FIG. 2, a subsequent Step 5 of the cover, in particular by means of a compression molding process, upset. In this process, the underside 6 of the carrier film 2 lies on one flat mold base, so that the channels 11 are closed from below. On the Top 3 is then placed on a corresponding counter shape and then the Plastic mass introduced into the mold. In this process, the IC 4 and the corresponding connection points surrounded by the plastic mass. The Plastic mass also flows into the openings 12, undercuts 16 and Channels 11 into it. As a result, cover material also reaches the back 6 of the Carrier film 2 in the area of the channels 11, whereby the locking areas 10 in are essentially completely surrounded by the masking compound. Especially if the base film has a bad tendency to bind to the cover plastic has a secure adherence of the cover 5 achieved, which ensures permanent protection of the IC's 4.

At this point it should be mentioned that the base film 2 made of different materials can exist. It is quite possible to use contacts 7 as carrier film 2 e.g. to train as a leadframe.

Another preferred embodiment of the invention will now be described with reference to FIG explained in more detail. It only points to the main differences from the above Embodiment received. For the same and similar components, the same Reference numbers used.

The punch mask shown in FIG. 3 represents an embodiment in which the Locking areas 10 and locking openings 12 circular along a circular line K are arranged. The circular line K is also the center line M of the Locking openings 12 and locking areas 10. The locking openings 12 have in essentially a similar shape to that in the previously described Embodiment and surround a recording area 16 on which the IC 4th is arranged.

Furthermore, a circular line A is drawn in dash-dotted lines, which the later Outside diameter of the applied cover 5 reproduces. Except for Cover 5 are still relief slots 17, which are concentric with the Locking openings 12 are arranged and additional bending loads from the Keep cover 5 away.

The two contact surfaces 18 and 19 are located on the carrier film 2 Contact surfaces 18 and 19 must have electrical isolation. This Potential isolation is established through a potential isolation channel 20. This separates the module area surrounded by the boundary channels 21 into two areas (according to FIG. 3 a left area 22 and a right area 23).

The potential isolation channel 20 begins on the side of the contact surface 19 and runs into the Area of the cover 5 into an upper locking opening 12. The separation channel 20 extends below the cover 5 essentially (with two exceptions, which are described in more detail below) such that the receiving area 16 for Recording of the IC 4 is completely assigned to the left area 22. Starting from a lower locking opening 12, the separation channel 20 again leaves the cover area.

The potential isolation channel 20 has a near the edge region of the cover 5 separable web 32 which connects the areas 22, 23 together. This Web 32 remains in the isolation channel 20 until the cover 5 is cured. The web 32 is then punched out. The point is the covering material does not pass through the potential separation channel 20 from the covering area 16 can flow out.

Two locking openings 12 are evenly distributed at four points by one Breakthrough 24 connected together. The opening 24 extends from each below the cover 5 to outside the circular line A, so that four over the Circular line A projecting hold-down tongues 25 are formed. The special at the right side of the module area is that the openings 24 part of the potential isolation channel 20.

The film material shown in Figure 3 is by a punching process according to the Stamped pattern of this figure is stamped so that the module area is different from the Border channels 21 is delimited, clearly highlights. Then in one Embossing step by means of a ring stamp with a trapezoidal cross-section into the circular line K as a center line having ring channel 11 on the rear side 6 of the carrier film 2 embossed. The hold-down tongues 25 serve to fix the Recording area so that it remains centered on the channel 11.

In a subsequent process step, the top 3 of the carrier film 2 the IC 4 put on and connected to the contact points 18 and 19.

The carrier material is then transferred to a compression molding station, in turn Press the hold-down device on the tongues 25 and on the back 6 of the carrier material there is a flat shaped disc and on the top one corresponding to the Cover form adapted die is placed. Then cover material introduced into the mold via the sprue channel 31 indicated by dash-dotted lines. The Cover material surrounds the IC 4 and penetrates into the locking openings 12 and fills the Ring channel 11. The locking areas 10 are then completely in the covering material embedded, and by the cover material located on the back 6 in Ring channel 11 securely connects cover 5 to carrier film 2. The web 32 ensures during this process that the covering material is not on the the side opposite the sprue channel 31 in the region of the potential separation channel 20 can flow out.

The module 1 can then be punched out.

Another embodiment of the present invention is illustrated in FIGS Invention explained in more detail. Again, for the same and similar components the same reference numerals are used. It only highlights the main differences received.

The main difference is that the locking areas 10 are straight Have transverse sides 14, which comprise an angle α of 90 ° to the longitudinal sides. The locking opening 12 therefore has a rectangular shape in plan view.

It can be seen very clearly from FIG. 9 how the covering material Locking areas 10 surrounds. On the back 6 is only a strip 26 of that Recognize cover material that is flush with the back 6, which makes this is completely flat.

With reference to Figures 10 and 11, the use of an inventive Chip module 1 explained in more detail in a chip card.

FIG. 10 shows a basic chip card body 26 which is milled out Has receiving pocket 27 for receiving the chip module 1 on its top. The The receiving pocket 27 is of stepped design and has a lower depth Contact area 28 on. With the contacts 29 of the contact area 28 is one Antenna coil 30 connected, which is embedded in the card base body 26.

The chip module 1 is inserted into the receiving pockets 27, the cover 5 points downwards and the contact surfaces 18 and 19 with the contacts 29 in Connect. In any way, the chip module 1 in the Anchoring pocket 27 anchored. This can e.g. by laminating an additional one Film.

It is a contactless chip card that is operated by induction becomes. Such a method is suitable e.g. also for the production of a hybrid card, if on the back 6 of the chip module 1 corresponding contact tracks are upset. But simple contact chip cards are also in this way producible, which need not have antenna coils 30.

Due to the fact that the cover 5 is anchored to the carrier film 2 takes place essentially in the plane of the carrier film 2, too Bending stresses along the bending line of the carrier film 2 are only slight Affect the locking of the cover 5. This will create a permanent sealing of the IC's 4 on the carrier film 2 achieved, even if the Cover 5 is attached to the carrier film 2 only on one side.

Claims (16)

Chip module (1) for a chip card with a carrier substrate (2), at least one IC (4) arranged on the carrier substrate (2) and a cover covering the IC (4) and connected to the carrier substrate (2), preferably by compression molding ( 5), the carrier substrate (2) having at least one opening (12), the edge region (14) of which is at least partially formed to form at least one undercut (11, 16) and the covering material at least in some regions into the opening (12) and Undercut (11, 16) has flowed in, and wherein the at least one undercut (11, 16) is formed by embossing depressions on the rear side (6) of the carrier film (2) in such a way that corresponding elevations (10 ) are formed so that the deformed edge regions (14) protrude beyond the plane spanned by the carrier substrate (2), characterized in that at least some of the edge regions (14) projecting upward have a Wi Nkel (α) of less than 90 ° to an adjacent flat edge region (13). Chip module (1) according to claim 1, characterized in that the carrier substrate (2) is a carrier film. Chip module (1) according to claim 2, characterized in that the carrier film (2) is a lead frame. Chip module (1) according to one of Claims 1 to 3, characterized in that
that the IC (4) on an upper side (3) of the carrier film (2) and the at least one undercut (11, 16) on a rear side (6) of the carrier film (2) are arranged. Chip module (1) according to one of Claims 1 to 4, characterized in that
that the covering material in the undercuts (11, 16) and the openings (12) merges substantially flat into the back (6) of the carrier film (2). Chip module (1) according to one of Claims 1 to 5, characterized in that
that the undercuts (11, 16) are designed as a channel (11) or channels (11) arranged on the rear side (6) of the carrier film (2). Chip module (1) according to claim 6, characterized in that a channel (11) extends from one opening (12) to the next opening (12). Chip module (1) according to one of claims 1 to 7, characterized in
that the openings (12) are arranged on a circular arc line (K) and an essentially triangular or trapezoidal channel (11) with the circular arc line (K) is impressed as a center line in the carrier substrate (2). Chip module (1) according to one of Claims 1 to 8, characterized in that the openings (12) and the channels (11) delimit a receiving area (16) on which the at least one IC (4) is applied. Chip module (1) according to claim 9, characterized in
that the openings (12) are grouped around the receiving area (16) essentially in the form of an n-corner. Chip module (1) according to one of claims 1 to 10, characterized in that
that the openings (12) have an n-shaped and / or circular cross section. Chip module (1) according to one of claims 1 to 11, characterized in that
that at least two openings (12) are connected to one another by an opening (24) such that the material area of the carrier film (2) located between the at least two openings (12) and delimited by the opening (24) as a hold-down tongue (25) the cover (5) protrudes laterally. Chip module according to claim 12, characterized in
that at least one potential isolation channel (20) is provided which divides the carrier film (2) into separate areas (22, 23) at least in the area of the cover (5), at least one opening (24) being part of the potential isolation channel (20). Chip module (1) according to claim 13, characterized in
that the potential separation channel (20) in the vicinity of the edge region of the cover (5) has a separable web (32) which connects the regions (22, 23) to one another. Chip module (1) according to one of Claims 1 to 14, characterized in that
that outside of the cover (5) and around it spaced relief slots (17) are arranged. Chip card with a chip module (1) according to one of Claims 1 to 15.

Images